There was no line at the Hope Street post office in Stamford on a recent Thursday afternoon, but customers came in twos and threes and left in an efficient manner.

Stamford resident Don Williams waited just a few minutes to consult briefly with Jonette Scott, the sales and service associate on duty, about the best way to send an envelope containing a photo. This was one of his once-or-twice yearly visits to the post office.

"It's not often," Williams said.

Judging by the numbers, bi-annual customers like Williams are becoming more and more common. The U.S. Postal Service recently announced a $1.9 billion net loss for the fiscal second quarter, the same loss incurred during the same period of 2013. The loss is due, in large part, to the declining volume of high-margin first-class mail, the Postal Service noted in a press release. First-class mail volume fell 4.1 percent in the second quarter, while standard mail volume increased by just 0.5 percent.

"This is our bread and butter product," said Christine Dugas, a spokeswoman for the U.S. Postal Service. "Now that that volume is declining, we're seeing the loss in revenue."

However, e-commerce is driving at least one aspect of the Postal Service in the right direction: shipping. Revenue from shipping and packaging increased $252 million, or 8 percent from last year's quarter. Package volume increased 7.3 percent. The agency is working to capitalize on this demand for shipping by offering customers options like increased tracking and Sunday delivery, according to the release.

Scott has regularly seen an increase in customers claiming online orders in her day-to-day business with the Postal Service. She was recently transferred to the Hope Street location from the Camp Ave. post office, where a greater number of customers conduct their shipping transactions, she said.